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The Portuguese Paradox: why do some inhabitants of Portugal appear to live so long when their diet is based on whey cheese?

Publication . Tavares, Tânia G.; Malcata, F. Xavier

The remarkable longevity of people in specific regions of Portugal, whose diets are based on whey cheese, has puzzled researchers for quite some time. Our data indicate that several oligopeptides are released from glycomacropeptide (originated in j-casein) and a-lactalbumin – and one surprisingly from b-lactoglobulin, by plant proteases previously used in cheesemaking. A few of such peptides (e.g. DKVGINYW, KGYGGVSLPEW and DAQSAPLRVY) exhibit unusually strong antihypertensive roles in vitro, following generation in situ or synthesis de novo. The activities of the latter two are not significantly affected by simulated gastrointestinal digestion, despite undergoing partial hydrolysis. This piece of information is rather promising toward more comprehensive attempts to scientifically rationalise this Portuguese Paradox.

2012Journal article

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Manufacture of bioactive peptide-rich concentrates from whey: characterization of pilot process

Publication . Tavares, Tânia G.; Amorim, Manuela; Gomes, David; Pintado, Manuela E.; Pereira, Carlos D.; Malcata, F. Xavier

This work was focused on the manufacture, at pilot scale, of cow whey protein and peptide concentrates, using selective filtration techniques—associated with hydrolysis brought about by proteolytic enzymes from Cynara cardunculus aqueous extracts, using as (optimal) conditions an enzyme/substrate ratio of 1.6% v/v, a pH of 5.2, a temperature of 55 C and an incubation time of 7 h. The profiles of proteins and peptides were assessed by liquid chromatography and electrophoresis; ca. 87% of a-lactalbumin was hydrolyzed, but essentially no degradation of b-lactoglobulin (b-Lg) was observed. A bioactive peptide concentrate, its fraction below 3 kDa and a b-Lg-rich fraction were obtained as final products, containing ca. 73, 43 and 91% w/w protein (on a total solid mass basis). All these fractions were low in lactose and salt, and their microbial loads were reduced. Said fractions are high added-value products, so they can be used as nutritional and functional ingredients—thus yielding an economically viable alternative for upgrade of whey.

2012Journal article

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Antinociceptive and anti-inflammatory effects of novel dietary protein hydrolysate produced from whey by proteases of Cynara cardunculus

Publication . Tavares, T. G.; Spindola, H.; Longato, G.; Pintado, M. E.; Carvalho, J. E.; Malcata, F. X.

Antinociceptive and anti-inflammatory effects of a peptide concentrate mix (PepC) obtained from whey protein, via hydrolysis with cardosins from Cynara cardunculus, was tested in vivo. The antinociceptive effect was assessed using writhing, hot-plate and formalin tests in mice, and the anti-inflammatory effect using the paw oedema test. PepC at 300 mg kg(-1) bw conveyed a significant result in the writhing test when co-administered with 1 and 3 mg kg(-1) bw indomethacin, similar to administration of higher doses of indomethacin alone. Conversely, no statistically significant differences were observed in the paw oedema test when the same PepC concentration was co-administered with dexamethasone at 3, 10 and 30 mg kg(-1) bw. PepC at 1000 mg kg(-1) bw did not cause any remarkable outcome in the hot-plate test. PepC appears to possess anti-inflammatory and peripheral antinociceptive activities, so it may be a candidate for nutraceutical ingredient.

2013Journal article

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Invited review: physiological properties of bioactive peptides obtained from whey proteins

Publication . Madureira, A. R.; Tavares, T.; Gomes, A. M. P.; Pintado, M. E.; Malcata, F. Xavier

Processing of whey proteins yields several bioactive peptides that can trigger physiological effects in the human body: on the nervous system via their opiate and ileum-contracting activities; on the cardiovascular system via their antithrombotic and antihypertensive activities; on the immune system via their antimicrobial and antiviral activities; and on the nutrition system via their digestibility and hypocholesterolemic effects. The specific physiological effects, as well the mechanisms by which they are achieved and the stabilities of the peptides obtained from various whey fractions during their gastrointestinal route, are specifically discussed in this review.

2010Journal article

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Optimisation, by response surface methodology, of degree of hydrolysis and antioxidant and ACE-inhibitory activities of whey protein hydrolysates obtained with cardoon extract

Publication . Tavares, T. G.; Contreras, M. M.; Amorim, M.; Martín-Álvarez, P. J.; Pintado, M. E.; Recio, I.; Malcata, F. X.

The hydrolysis of bovine whey protein concentrate (WPC), alpha-lactalbumin (alpha-La) and caseinomacropeptide (CMP), by aqueous extracts of Cynara cardunculus, was optimized using response surface methodology. Degree of hydrolysis (DH), angiotensin-converting enzyme (ACE)-inhibitory activity and antioxidant activity were used as objective functions, and hydrolysis time and enzyme/substrate ratio as manipulated parameters. The model was statistically appropriate to describe ACE-inhibitory activity of hydrolysates from WPC and alpha-La, but not from CMP. Maximum DH was 18% and 9%, for WPC and alpha-La, respectively. 50% ACE-inhibition was produced by 105.4 (total fraction) and 25.6 mu g mL(-1) (<3 kDa fraction) for WPC, and 47.6 (total fraction) and 22.5 mu g mL(-1) (<3 kDa fraction) for alpha-La. Major peptides of fractions exhibiting ACE-inhibition were sequenced. The antioxidant activities of WPC and alpha-La were 0.96 +/- 0.08 and 1.12 +/- 0.13 mmol trolox equivalent per mg hydrolysed protein, respectively.

2011Journal article

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